1. Technical Field
The present invention relates to an actuator, a robot hand, a robot, an electronic component conveying apparatus, an electronic component testing apparatus, and a printer.
2. Related Art
As a driving method for an actuator in the past, there is known a method of exciting a piezoelectric body in two vibration modes, moving a protrusion section provided at an end of the piezoelectric body on an elliptical track, and driving a driven body, which comes into contact with the protrusion section, in a predetermined direction. In the actuator, in order to urge the piezoelectric body to the driven body, a side surface side of a vibrating surface of the piezoelectric body is pressed against and held in a holding case via an elastic member and the holding case is urged in the direction of the driven body by urging means, whereby the piezoelectric body is urged to the driven body (WO2007/80851 (Patent Literature 1) and WO2008/93799 (Patent Literature 2)). Further, JP-A-2007-189900 (Patent Literature 3) discloses a configuration for holding a part of an outer edge portion of a piezoelectric body, urging a holding case for holding the piezoelectric body to a driven body, and urging the piezoelectric body to the driven body.
However, in Patent Literatures 1 and 2, the elastic member for holding the piezoelectric body is arranged to limit a vibrating direction of the piezoelectric body, in particular, vibration with respect to bending vibration. Therefore, it is likely that the vibration of the piezoelectric body leaks to the holding case through the elastic member and a lot of driving energy for the driven body is lost. In Patent Literature 3, it is likely that a vibration leak from a guiding section of the holding case for holding the piezoelectric body occurs and a lot of driving energy for the driven body is lost.